Backslash key and Cmd+key input not working on MacOS with Japanese Macbook

[Lokechu]

I am unable to input a backslash character and also unable to copy/paste using keyboard shortcuts such as Cmd+c/Cmd+v while using a Japanese MacBook.

To Reproduce
Steps to reproduce the behavior:

1. Open Neovide
2. Try to type backslash character while in input mode by holding option and pressing the ¥ key.
3. Instead of \ character being printed to the buffer, it switches from input to normal mode as if ESC had been pressed.

Expected behavior
\ character should be printed to the buffer

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: macOS 14.4.1
• Neovide Version: 0.12.2
• Neovim Version: 0.10.0-dev-3050+gcb24a3907

TRACE [neovide::channel_utils] neovim_handler WindowViewport { grid: 2, top_line: 0.0, bottom_line: 2.0, current_line: 0.0, current_column: 0.0, line_count: Some(1.0), scroll_delta: Some(0.0) }
TRACE [neovide::channel_utils] neovim_handler Flush
TRACE [neovide::editor] Image flushed
TRACE [neovide::editor] send_batch
TRACE [neovide::renderer::rendered_window] Handling Viewport 2
TRACE [neovide::renderer::fonts::caching_shaper] Shaping text: "INSERT"
TRACE [neovide::window::keyboard_manager] KeyEvent {
physical_key: Code(
KeyI,
),
logical_key: Character(
"i",
),
text: None,
location: Standard,
state: Released,
repeat: false,
platform_specific: KeyEventExtra {
text_with_all_modifiers: Some(
"i",
),
key_without_modifiers: Character(
"i",
),
},
}
TRACE [neovide::window::keyboard_manager] KeyEvent {
physical_key: Code(
AltLeft,
),
logical_key: Named(
Alt,
),
text: None,
location: Left,
state: Pressed,
repeat: false,
platform_specific: KeyEventExtra {
text_with_all_modifiers: None,
key_without_modifiers: Named(
Alt,
),
},
}
TRACE [neovide::window::keyboard_manager] Modifiers { state: ModifiersState(ALT), pressed_mods: ModifiersKeys(LALT) }
TRACE [neovide::window::keyboard_manager] KeyEvent {
physical_key: Code(
IntlYen,
),
logical_key: Character(
"\",
),
text: Some(
"\",
),
location: Standard,
state: Pressed,
repeat: false,
platform_specific: KeyEventExtra {
text_with_all_modifiers: Some(
"\",
),
key_without_modifiers: Character(
"¥",
),
},
}
TRACE [neovide::window::keyboard_manager] Key pressed <M-¥> ModifiersState(ALT)
TRACE [neovide::channel_utils] UICommand Serial(Keyboard("<M-¥>"))
TRACE [neovide::bridge::ui_commands] In Serial Command
TRACE [neovide::bridge::ui_commands] Keyboard Input Sent: <M-¥>
TRACE [neovide::bridge::handler] Neovim notification: "redraw"
TRACE [neovide::channel_utils] neovim_handler GridLine { grid: 4, row: 0, column_start: 95, cells: [GridLineCell { text: "\", highlight_id: Some(1426), repeat: None }] }
TRACE [neovide::channel_utils] neovim_handler ModeChange { mode: Normal, mode_index: 0 }
TRACE [neovide::channel_utils] neovim_handler Flush
TRACE [neovide::bridge::handler] Neovim notification: "redraw"
TRACE [neovide::channel_utils] neovim_handler GridLine { grid: 4, row: 0, column_start: 95, cells: [GridLineCell { text: " ", highlight_id: Some(1426), repeat: None }, GridLineCell { text: " ", highlight_id: Some(0), repeat: Some(0) }] }
TRACE [neovide::channel_utils] neovim_handler Flush
TRACE [neovide::editor] Image flushed
TRACE [neovide::editor] send_batch
TRACE [neovide::editor] Image flushed
TRACE [neovide::editor] send_batch
TRACE [neovide::bridge::handler] Neovim notification: "redraw"
TRACE [neovide::channel_utils] neovim_handler GridLine { grid: 1, row: 59, column_start: 0, cells: [GridLineCell { text: " ", highlight_id: Some(679), repeat: None }, GridLineCell { text: "N", highlight_id: None, repeat: None }, GridLineCell { text: "O", highlight_id: None, repeat: None }, GridLineCell { text: "R", highlight_id: None, repeat: None }, GridLineCell { text: "M", highlight_id: None, repeat: None }, GridLineCell { text: "A", highlight_id: None, repeat: None }, GridLineCell { text: "L", highlight_id: None, repeat: None }, GridLineCell { text: " ", highlight_id: None, repeat: None }, GridLineCell { text: "\u{e0b0}", highlight_id: Some(1454), repeat: None }, GridLineCell { text: " ", highlight_id: Some(695), repeat: None }, GridLineCell { text: "\u{f487}", highlight_id: None, repeat: None }, GridLineCell { text: " ", highlight_id: None, repeat: None }, GridLineCell { text: "3", highlight_id: None, repeat: None }, GridLineCell { text: " ", highlight_id: None, repeat: None }, GridLineCell { text: " ", highlight_id: Some(681), repeat: Some(75) }, GridLineCell { text: "\u{e712}", highlight_id: None, repeat: None }, GridLineCell { text: " ", highlight_id: None, repeat: None }, GridLineCell { text: "\u{e0b2}", highlight_id: Some(1441), repeat: None }, GridLineCell { text: " ", highlight_id: Some(680), repeat: None }, GridLineCell { text: "T", highlight_id: None, repeat: None }, GridLineCell { text: "o", highlight_id: None, repeat: None }, GridLineCell { text: "p", highlight_id: None, repeat: None }, GridLineCell { text: " ", highlight_id: None, repeat: None }, GridLineCell { text: "\u{e0b2}", highlight_id: Some(1442), repeat: None }, GridLineCell { text: " ", highlight_id: Some(679), repeat: Some(3) }, GridLineCell { text: "1", highlight_id: None, repeat: None }, GridLineCell { text: ":", highlight_id: None, repeat: None }, GridLineCell { text: "1", highlight_id: None, repeat: None }, GridLineCell { text: " ", highlight_id: Some(679), repeat: Some(2) }, GridLineCell { text: " ", highlight_id: Some(0), repeat: Some(0) }] }
TRACE [neovide::channel_utils] neovim_handler WindowViewport { grid: 2, top_line: 0.0, bottom_line: 2.0, current_line: 0.0, current_column: 0.0, line_count: Some(1.0), scroll_delta: Some(0.0) }
TRACE [neovide::channel_utils] neovim_handler Flush
TRACE [neovide::editor] Image flushed
TRACE [neovide::editor] send_batch
TRACE [neovide::renderer::rendered_window] Handling Viewport 2
TRACE [neovide::window::keyboard_manager] KeyEvent {
physical_key: Code(
IntlYen,
),
logical_key: Character(
"\",
),
text: None,
location: Standard,
state: Released,
repeat: false,
platform_specific: KeyEventExtra {
text_with_all_modifiers: Some(
"\",
),
key_without_modifiers: Character(
"¥",
),
},
}
TRACE [neovide::window::keyboard_manager] KeyEvent {
physical_key: Code(
AltLeft,
),
logical_key: Named(
Alt,
),
text: None,
location: Left,
state: Released,
repeat: false,
platform_specific: KeyEventExtra {
text_with_all_modifiers: None,
key_without_modifiers: Named(
Alt,
),
},
}
TRACE [neovide::window::keyboard_manager] Modifiers { state: ModifiersState(0x0), pressed_mods: ModifiersKeys(0x0) }
TRACE [neovide::channel_utils] UICommand Parallel(FocusLost)

Additional context
Macbook is a M1 Apple Silicon model. The keyboard layout is JIS (Japanese). The same result happens whether using the built-in keyboard of the Macbook or when using an external Keychron keyboard (Also JIS layout).

[Lokechu]

While discussing this issue with @fredizzimo in the discord support channel, it was suggested to use the following key remapping:

  vim.keymap.set(
      {'n', 'v', 's', 'x', 'o', 'i', 'l', 't', 'c'},
      '<M-¥>',
      '\\',
      { noremap = true, silent = true }
  )
end

I don't understand the root cause though since the log shows they key event correctly and even the return of:
text_with_all_modifiers: Some( "\", )

However, this workaround does result in the expected behavior and I am satisfied as a result.

[fredizzimo]

The core issue is that if https://neovide.dev/configuration.html#macos-option-key-is-meta, is set then it will prefer the <M-¥> variation and sent that to Neovim. On keyboards with two alt-keys it can be worked around in Neovim 0.13.0 by specifying that only one of the keys does that. But since your laptop only has one alt key, then a custom mapping has to be used for the keys you want to use as regular characters.